Ankle sprains occur when a ligament in the joint is over stretched or torn, often from a sudden twist or awkward landing. They are among the most common injuries in soccer and can lead to pain and stability problems lasting months or even years for some.

Though there have been a number of studies into why athletes suffer sprains, few have focused on soccer players, said George Vagenas, from the University of Athens and lead researcher, and colleagues, who published their findings in the American Journal of Sports Medicine.

The researchers did pre-season tests of ankle strength and stability in 100 players from four professional soccer teams in Greece, then followed the players over the next 10 months to see who would get hurt on the field.

Seventeen players suffered one or more non-contact sprains during the season. Those with considerable strength differences between their left and right ankles were nine times as likely to suffer sprains as those whose ankles were about the same strength.

When a player cuts or lands from a jump, it's important to have symmetrical activation of the two sets of ankle muscles to help the joints absorb the impact and prevent damage, Vagenas told Reuters Health by email.

"All soccer players, professionals or not, must be evaluated during the pre-seasonal period by sports specialists for verification of potential functional asymmetry of the ankle joint," he said.

Sports medicine experts said the report has an important message for amateur athletes as well.

"This study does suggest that if soccer players want to lower their risk of suffering ankle sprains, then they should strengthen their ankle musculature evenly, so that they have a good balance between both legs," said Erik Wikstrom, an expert in ankle sprains at the University of North Carolina at Charlotte.

"Proper balance between the lower extremities is very important."

Earlier studies have shown that both lace-up ankle braces and balance training on a "wobble board" can help stave off injuries to the joint.

"I tell people to go ahead and balance on one leg, then the other for two to three minutes," said Timothy McGuine, a sports medicine specialist at the University of Wisconsin-Madison, who added that two to three times a week is a good start.

The Greek researchers also found that heavy players were more prone to sprains, which makes sense given the extra force their ankles have to absorb when they land or cut.

Apart from keeping a healthy weight, McGuine told Reuters Health that it's important to learn how to land properly too.

"Don't land stiff legged. We want a soft foot strike."

SOURCE: bit.ly/MoUQb5

(Reporting from New York by Frederik Joelving at Reuters Health; Editing by Elaine Lies and Ed Lane)

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